precision mediump float;
varying vec4 v_Color;
uniform sampler2D qpicture;
varying vec2 v_texCoord;
uniform vec2 u_resolution;

varying float v_time;
mat2 rotation2d(float angle) {
  float s = sin(angle);
  float c = cos(angle);

  return mat2(
    c, -s,
    s, c
  );
}
void main(void){
  vec2 texCoord = (gl_FragCoord.xy*2.-u_resolution)/min(u_resolution.x,u_resolution.y);
  vec4 texturecolor =  texture2D(qpicture, texCoord*rotation2d(v_time));
  gl_FragColor=vec4(texturecolor);
}